U.S. patent application number 11/302423 was filed with the patent office on 2006-07-20 for low pain penetrating member.
Invention is credited to Don Alden, Dirk Boecker, Dominique M. Freeman, Michael Wittig.
Application Number | 20060161194 11/302423 |
Document ID | / |
Family ID | 35782096 |
Filed Date | 2006-07-20 |
United States Patent
Application |
20060161194 |
Kind Code |
A1 |
Freeman; Dominique M. ; et
al. |
July 20, 2006 |
Low pain penetrating member
Abstract
Reducing the volume or drag on skin or sharpness of the
penetrating member entering the wound during the cutting process
will reduce the pain associated with lancing, and result in less
power desired for retraction of the penetrating member from the
skin. A variety of other penetrating member configuration as shown
in the application.
Inventors: |
Freeman; Dominique M.; (La
Honda, CA) ; Alden; Don; (Sunnyvale, CA) ;
Wittig; Michael; (Palo Alto, CA) ; Boecker; Dirk;
(Palo Alto, CA) |
Correspondence
Address: |
HELLER EHRMAN LLP
275 MIDDLEFIELD ROAD
MENLO PARK
CA
94025-3506
US
|
Family ID: |
35782096 |
Appl. No.: |
11/302423 |
Filed: |
December 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US04/18705 |
Jun 14, 2004 |
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11302423 |
Dec 12, 2005 |
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60477813 |
Jun 11, 2003 |
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Current U.S.
Class: |
606/185 |
Current CPC
Class: |
A61B 5/1411 20130101;
A61B 5/150022 20130101; A61B 5/157 20130101; A61B 5/150175
20130101; A61B 5/150427 20130101; A61B 5/15161 20130101; A61B
5/150282 20130101; A61B 5/150167 20130101; A61B 5/150511 20130101;
A61B 5/15151 20130101; A61B 5/411 20130101; A61B 5/15123
20130101 |
Class at
Publication: |
606/185 |
International
Class: |
A61B 17/34 20060101
A61B017/34 |
Claims
1. A device comprising: a penetrating member for piercing
tissue.
2. The device of claim 1 wherein the penetrating member is
configured to reduce the volume or friction of a penetrating member
shaft in the skin.
3. The device of claim 1 wherein the penetrating member comprises a
distal tip having a first cutting facet and a second cutting
facet.
4. The device of claim 1 wherein primary facet length of the
penetrating member is less than about 1.0 mm.
5. The device of claim 1 wherein primary facet length of the
penetrating member is more than about 2.0 mm.
6. The device of claim 1 wherein a ratio of primary facet length to
side facet length is less than 2.24:0.63.
7. The device of claim 1 wherein a ratio of primary facet length to
side facet length is less than 2:1.
8. The device of claim 1 wherein a ratio of primary facet length to
side facet length is less than 2:1, and wherein primary facet
length of the penetrating member is less than about 1.0 mm.
9. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 1.60 mm.
10. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 1.70 mm.
11. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 1.70 mm.
12. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 1.80 mm.
13. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 1.90 mm.
14. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 2.00 mm.
15. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 2.10 mm.
16. The device of claim 1 wherein the penetrating member has a
primary facet length greater than about 2.20 mm.
17. The device of claim 1 wherein the penetrating member has a
primary facet angle less than about 7.0 degrees.
18. The device of claim 1 wherein the penetrating member has a
primary facet angle less than about 7.5 degrees.
19. The device of claim 1 wherein the penetrating member has a
bevel joint length less than about 0.24 mm.
20. The device of claim 1 wherein the penetrating member has a
bevel joint angle is less than about 16 degrees.
21. The device of claim 1 wherein the penetrating member has a
bevel joint angle is less than about 15.5 degrees.
22. The device of claim 1 wherein the penetrating member has a
diameter less than about 0.32 mm.
23. The device of claim 1 wherein the penetrating member has a
diameter less than about 0.30 mm.
24. The device of claim 1 wherein the penetrating member has a
cutting efficiency sufficient to bring at least 1 micro liter of
blood to a skin surface after penetrating about 600 to 800 microns
into the skin.
25. The device of claim 1 wherein the penetrating member has a
cutting efficiency sufficient to bring at least 1 micro liter of
blood to a skin surface after peentratign about 0.5 to 1.0 mm into
the skin.
26. The device of claim 1 wherein the penetrating member comprises
a shaft having a half-round bar stock.
27. The device of claim 1 wherein the penetrating member has a oval
cross-section.
28. The device of claim 1 wherein a portion of the penetrating
member has a first cross-sectional volume and a second
cross-sectional volume greater than the first.
29. The device of claim 1 wherein a front end portion has a smashed
end configuration.
30. The device of claim 1 wherein the penetrating member has a
splined cross-section.
31. The device of claim 1 wherein the penetrating member is a bare
lancet without any molded attachments.
32. The device of claim 1 wherein the penetrating member further
comprises a molded attachment coupled to a shaft portion of the
penetrating member.
33. The device of claim 1 further comprising an electric
penetrating member drive to advance the penetrating member into
tissue.
34. A cartridge containing a plurality of penetrating member as
described in claim 1.
35. A radial cartridge containing a plurality of penetrating member
as described in claim 1.
36. A method of body fluid sampling for use on tissue, the method
comprising: using a penetrating member having a reduced volume;
advancing said penetrating member into the tissue to create a wound
channel.
37. A method for controlling depth of penetrating member motion
into a patient, said method comprising: advancing a penetrating
member exhibiting reduced penetration resistance.
Description
BACKGROUND OF THE INVENTION
[0001] Lancing devices are known in the medical health-care
products industry for piercing the skin to produce blood for
analysis. Typically, a drop of blood for this type of analysis is
obtained by making a small incision in the fingertip, creating a
small wound, which generates a small blood droplet on the surface
of the skin.
[0002] Early methods of lancing included piercing or slicing the
skin with a needle or razor. Current methods utilize lancing
devices that contain a multitude of spring, cam and mass actuators
to drive the lancet. These include cantilever springs, diaphragms,
coil springs, as well as gravity plumbs used to drive the lancet.
The device may be held against the skin and mechanically triggered
to ballistically launch the lancet. Unfortunately, the pain
associated with each lancing event using known technology
discourages patients from testing. In addition to vibratory
stimulation of the skin as the driver impacts the end of a launcher
stop known spring based devices have the possibility of firing
lancets that harmonically oscillate against the patient tissue,
causing multiple strikes due to recoil. This recoil and multiple
strikes of the lancet is one major impediment to patient compliance
with a structured glucose monitoring regime. Known lancets also
have a configuration which may contribute in part to the pain
associated with lancing for body fluid generation.
[0003] Additionally, known lancets have geometries that may
contribute to the pain associated with lancing. Most known lancets
fail to balance between reducing pain but creating a wound
generating sufficient blood or other body fluid flow. Accordingly,
there is a need for improved penetrating members for addressing
these deficiencies.
SUMMARY OF THE INVENTION
[0004] The present invention provides solutions for at least some
of the drawbacks discussed above. Specifically, some embodiments of
the present invention provide an improved penetrating member
configuration for penetration into tissue. Some embodiments of
these penetrating members may be used with intelligent control of
the velocity profile that will increase the likelihood of
spontaneous blood generation. At least some of these and other
objectives described herein will be met by embodiments of the
present invention.
[0005] In one aspect of the present invention, the invention
relates to minimizing the pain of skin lancing based on reducing
the volume of penetrating member material interacting with the skin
during the cutting process. This may be achieved through surface
modification or geometry changes such that cutting efficiency is
increased.
[0006] Reducing the volume or drag on skin or sharpness of the
penetrating member entering the wound during the cutting process
will reduce the pain associated with lancing, and result in less
power desired for retraction of the penetrating member from the
skin.
[0007] A further understanding of the nature and advantages of the
invention will become apparent by reference to the remaining
portions of the specification and drawings.
[0008] The system may further comprise means for coupling the force
generator with one of the penetrating members.
[0009] The system may further comprise a penetrating member sensor
positioned to monitor a penetrating member coupled to the force
generator, the penetrating member sensor configured to provide
information relative to a depth of penetration of a penetrating
member through a skin surface.
[0010] The depth of penetration may be about 100 to 2500
microns.
[0011] The depth of penetration may be about 500 to 750
microns.
[0012] The depth of penetration may be, in this nonlimiting
example, no more than about 1000 microns beyond a stratum corneum
thickness of a skin surface.
[0013] The depth of penetration may be no more than about 500
microns beyond a stratum corneum thickness of a skin surface.
[0014] The depth of penetration may be no more than about 300
microns beyond a stratum corneum thickness of a skin surface.
[0015] The depth of penetration may be less than a sum of a stratum
corneum thickness of a skin surface and 400 microns.
[0016] The penetrating member sensor may be further configured to
control velocity of a penetrating member.
[0017] The active penetrating member may move along a substantially
linear path into the tissue.
[0018] The active penetrating member may move along an at least
partially curved path into the tissue.
[0019] The driver may be a voice coil drive force generator.
[0020] The driver may be a rotary voice coil drive force
generator.
[0021] The penetrating member sensor may be coupled to a processor
with control instructions for the penetrating member driver.
[0022] The processor may include a memory for storage and retrieval
of a set of penetrating member profiles utilized with the
penetrating member driver.
[0023] The processor may be utilized to monitor position and speed
of a penetrating member as the penetrating member moves in a first
direction.
[0024] The processor may be utilized to adjust an application of
force to a penetrating member to achieve a desired speed of the
penetrating member.
[0025] The processor may be utilized to adjust an application of
force to a penetrating member when the penetrating member contacts
a target tissue so that the penetrating member penetrates the
target tissue within a desired range of speed.
[0026] The processor may be utilized to monitor position and speed
of a penetrating member as the penetrating member moves in the
first direction toward a target tissue, wherein the application of
a launching force to the penetrating member is controlled based on
position and speed of the penetrating member.
[0027] The processor may be utilized to control a withdraw force to
the penetrating member so that the penetrating member moves in a
second direction away from the target tissue.
[0028] In the first direction, the penetrating member may move
toward the target tissue at a speed that is different than a speed
at which the penetrating member moves away from the target
tissue.
[0029] In the first direction the penetrating member may move
toward the target tissue at a speed that is greater than a speed at
which the penetrating member moves away from the target tissue.
[0030] The speed of a penetrating member in the first direction may
be the range of about 2.0 to 10.0 m/sec.
[0031] The average velocity of the penetrating member during a
tissue penetration stroke in the first direction may be about 100
to about 1000 times greater than the average velocity of the
penetrating member during a withdrawal stroke in a second
direction.
[0032] A further understanding of the nature and advantages of
the,invention will become apparent by reference to the remaining
portions~of the specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a side view of one embodiment of the invention,
which includes dimples impressed across the contact area of the
penetrating member.
[0034] FIG. 2 is a detail side view of the tip of the penetrating
member.
[0035] FIG. 3 is a side view of one embodiment of the invention,
which includes a splined cross-section.
[0036] FIG. 4 is a detail side view of the tip of the penetrating
member shown in FIG. 3.
[0037] FIG. 5 is a cross-sectional view of the shaft of the
penetrating member shown in FIG. 3.
[0038] FIG. 6 is a side view of a standard lancet design.
[0039] FIG. 7 is a detail side view of a standard lancet
design.
[0040] FIG. 8 is a front view of the lancet design of FIG. 6.
[0041] FIG. 9 is a sectional side view of the lancet design of FIG.
8.
[0042] FIG. 10 is a detail side view of the lancet design of FIG.
9, showing the addition of a layer of coating to the lancet.
[0043] FIG. 11 is a side view of one embodiment of the invention,
which includes a cross-section with cutouts on the bottom portion
of the penetrating member to reduce the area in contact with the
penetrated matter.
[0044] FIG. 12 is a detail side view of the penetrating member of
FIG. 1 1.
[0045] FIG. 13 is a cross-sectional view of section D-D of the
penetrating member of FIG. 11.
[0046] FIG. 14 is a cross-sectional view of section C-C of the
penetrating member of FIG. 11.
[0047] FIG. 15 is a side view of one embodiment of the invention
which includes a cross-section ground on either side of the bottom
portion of the penetrating member to reduce the area in contact
with the penetrated matter.
[0048] FIG. 16 is a detail side view of the penetrating member of
FIG. 15.
[0049] FIG. 17 is a cross-sectional view of section D-D of the
penetrating member of FIG. 15.
[0050] FIG. 18 is a cross-sectional view of section C-C of the
penetrating member of FIG. 15.
[0051] FIG. 19 shows a further embodiment of FIG. 15 for reducing
the volume of metal inside skin during the lancing event.
[0052] FIG. 20 shows yet another embodiment of the present
invention.
[0053] FIG. 21 shows the general elements of a penetrating member
tip.
[0054] FIG. 22 shows various embodiments of a penetrating member
tip.
[0055] FIG. 23 shows the portions and measurements of one
embodiment of the present invention.
[0056] FIGS. 24-29 are perspective views of various embodiments of
the present invention.
[0057] FIG. 30 is a table showing specific measurements of various
penetrating members.
[0058] FIG. 31 illustrates an embodiment of a controllable force
driver in the form of a cylindrical electric penetrating member
driver using a coiled solenoid -type configuration.
[0059] FIG. 32A illustrates a displacement over time profile of a
penetrating member driven by a harmonic spring/mass system.
[0060] FIG. 32B illustrates the velocity over time profile of a
penetrating member driver by a harmonic spring/mass system.
[0061] FIG. 32C illustrates a displacement over time profile of an
embodiment of a controllable force driver.
[0062] FIG. 32D illustrates a velocity over time profile of an
embodiment of a controllable force driver.
[0063] FIG. 33 is a diagrammatic view illustrating a controlled
feed-back loop.
[0064] FIG. 34 is a perspective view of a tissue penetration device
having features of the invention.
[0065] FIG. 35 is an elevation view in partial longitudinal section
of the tissue penetration device of FIG. 4.
[0066] FIGS. 36A-36G shows a method of penetrating tissue.
[0067] FIG. 37 shows one embodiment of disc for use with the
present invention.
[0068] FIG. 38 shows one view of the disc in a penetrating member
device.
[0069] FIG. 39 shows another embodiment of a device that may use a
disc as described in FIG. 37.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0070] The present invention provides a solution for body fluid
sampling. Specifically, some embodiments of the present invention
provides method for improving spontaneous blood generation. The
invention may be designed for use with a high density penetrating
member cartridge. It may use penetrating members of smaller size,
such as but not limited to diameter or length, than those of
lancets known in the art. The cutting surfaces of the penetrating
member may be configured for improved cutting. At least some of
these and other objectives described herein will be met by
embodiments of the present invention.
[0071] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention, as
claimed. It may be noted that, as used in the specification and the
appended claims, the singular forms "a", "an" and "the" include
plural referents unless the context clearly dictates otherwise.
Thus, for example, reference to "a material" may include mixtures
of materials, reference to "a chamber" may include multiple
chambers, and the like. References cited herein are hereby
incorporated by reference in their entirety, except to the extent
that they conflict with teachings explicitly set forth in this
specification.
[0072] In this specification and in the claims which follow,
reference will be made to a number of terms which shall be defined
to have the following meanings:
[0073] "Optional" or "optionally" means that the subsequently
described circumstance may or may not occur, so that the
description includes instances where the circumstance occurs and
instances where it does not. For example, if a device optionally
contains a feature for analyzing a blood sample, this means that
the analysis feature may or may not be present, and, thus, the
description includes structures wherein a device possesses the
analysis feature and structures wherein the analysis feature is not
present.
[0074] FIG. 1 is a side view of one embodiment of the invention,
which includes dimples impressed across the contact area of the
penetrating member.
[0075] FIG. 2 is a detail side view of the tip of the penetrating
member shown in Figure.
[0076] FIG. 3 is a side view of one embodiment of the invention,
which includes a splined cross-section.
[0077] FIG. 4 is a detail side view of the tip of the penetrating
member shown in FIG. 3.
[0078] FIG. 5 is a cross-sectional view of the shaft of the
penetrating member shown in FIG. 3.
[0079] FIG. 6 is a side view of a standard lancet design.
[0080] FIG. 7 is a detail side view of a standard lancet
design.
[0081] FIG. 8 is a front view of the lancet design of FIG. 6.
[0082] FIG. 9 is a sectional side view of the lancet design of FIG.
8.
[0083] FIG. 10 is a detail side view of the lancet design of FIG.
9, showing the addition of a layer of coating to the lancet.
[0084] FIG. 11 is a side view of one embodiment of the invention,
which includes a cross-section with cutouts on the bottom portion
of the penetrating member to reduce the area in contact with the
penetrated matter.
[0085] FIG. 12 is a detail side view of the penetrating member of
FIG. 11.
[0086] FIG. 13 is a cross-sectional view of section D-D of the
penetrating member of FIG. 11.
[0087] FIG. 14 is a cross-sectional view of section C-C of the
penetrating member of FIG. 11.
[0088] FIG. 15 is a side view of one embodiment of the invention
which includes a cross-section ground on either side of the bottom
portion of the penetrating member to reduce the area in contact
with the penetrated matter.
[0089] FIG. 16 is a detail side view of the penetrating member of
FIG. 15.
[0090] FIG. 17 is a cross-sectional view of section D-D of the
penetrating member of FIG. 15.
[0091] FIG. 18 is a cross-sectional view of section C-C of the
penetrating member of FIG. 15.
[0092] FIG. 19 A further embodiment of FIG. 15 for reducing the
volume of metal inside skin during the lancing event. Shaving the
material from the "back" of the penetrating member while
maintaining the cutting geometry and relation ship of the angles of
the secondary facets.
[0093] FIG. 20 Reducing the volume of metal entering the skin
during the lancing event by shaving material off the back and sides
of the penetrating member while maintaining the geometry of the
cutting tip (similar to FIGS. 15 and 19 but easier to grind for
manufacturing purposes).
[0094] FIGS. 1, 3, 12, and 15 show embodiments that provide
geometries designed to reduce the area of contact of the
penetrating member with the penetrated material. As a nonlimiting
example, FIGS. 1, 3, and 12 show embodiments that rely on the
skin's inability to conform to concave surfaces when stretched.
FIG. 15 shows an embodiment, which simply reduces the surface area
of the penetrating member: the shortest distance between two
points, a line, is constructed in place of curved section. The apex
of the lower portion of the penetrating member remains intact to
provide a high section moment of inertia to the penetrating member,
thereby maintaining penetrating member stiffness and tip stability.
Maintaining penetrating member stiffness is important for
minimizing lateral deflection of the tip, which is a primary
contributor to lancing pain.
[0095] The embodiment of the invention shown in FIG. 10 includes a
penetrating member coated with polytetrafluoroethylene. The
polytetrafluoroethylene coating serves to reduce the frictional
force desired to drive the penetrating member during entry.
Although polytetrafluoroethylene does not noticeably improve the
performance of very high speed projectiles, such as those designed
to penetrate armor, it is believed effective at reducing friction
on projectiles on low speeds. The polytetrafluoroethylene coating
also isolates the penetrated matter from the material of the
penetrating member. This is advantageous for avoiding a possible
contact allergic reaction to the material of the penetrating
member. For example, 303 stainless steel contains 9% nickel by
weight, and may induce a nickel allergy in a human coming into
contact with it. This type of allergy can also appear after
repeated contact with such a material, and once it appears it is
normally a chronic, lifelong condition. Polytetrafluoroethylene,
however, is one of the most non-reactive materials known, and does
not appear to cause such a condition.
[0096] In order to understand the factors controlling skin lancing,
a detailed understanding of the cutting efficiency and profile of
the penetrating member is desired. Creation of the wound channel
and geometry of the cut are factors controlling blood yield and
wound healing. Substantial effort has been put into understanding
the penetrating member geometry and dimensions with relation to
pain and blood yield.
[0097] FIG. 21 shows a penetrating member geometry. A variety of
controllable factors are known to result in painless, efficient
blood droplet yield from the skin surface. These factors include
the depth of penetrating member penetration to the vascular plexus;
the manner in which the skin is stabilized prior to penetrating
member impact and the geometry of the lancing device. Blood volume,
success rate, pain, and wound formation may be related to the
diameter, depth and facet geometry of the penetrating member tip.
The preferred geometry for cutting is a three-facet design shown
and this geometry is common in the industry. Manufacture of these
types of penetrating members is generally by taking a rod of a
given diameter (usually 250-760 mm diameter) and grinding 8 degrees
to the plane of the primary axis to create the primary facet. The
secondary facets are then created by rotating the shaft of the
penetrating member 15 degrees, and then rolling over 12 degrees to
the plane of the primary facet. Other possible geometries desire
altering the penetrating member's production parameters such as
shaft diameter, angles, and translation distance. The features of
the penetrating member tip affect lancing pain, cutting efficiency,
wound healing and blood volume. Cutting efficiency is governed by
the angle of the secondary facets.
[0098] Referring now to FIGS. 22 and 23, the facets lengths, angles
and diameter of common industry standard penetrating members have
been measured and are shown. Lancing pain and blood yield are
integrally related to these mechanical parameters. A common precept
is that the smaller the diameter of the penetrating member, the
less lancing pain is perceived. For a given amount of blood
however, the thin penetrating member must then go deeper to cut
more vessels to get the same amount of blood (this is discussed in
detail in the anatomy section). Consequently, a larger diameter
penetrating member with a shallow penetration will cut the desired
amount of blood vessels (capillaries) with less pain. Reducing the
volume of metal entering the finger, which is not associated with
the cutting diameter, may help reduce pain and reduce the amount of
"drag" or force desired to remove the penetrating member from the
finger. The ideas presented FIGS. 1-20 are various embodiments
directed at reducing the volume or friction of the penetrating
member shaft in the skin.
[0099] FIG. 22 shows facet geometry of penetrating members commonly
used for glucose spot monitoring.
[0100] FIG. 23A shows a drawing of relationship of facets and
angles. In one embodiment as shown more clearly in FIG. 23B, the
facet B has a length of about 0.84 mm and the bevel joint length C
is about 0.47 mm.
[0101] In order to understand the factors controlling skin lancing,
a detailed understanding of the cutting efficiency and profile of
the lancet is desired. Creation of the wound channel and geometry
of the cut are factors controlling blood yield and wound healing.
Substantial effort has been put into understanding the lancet
geometry and dimensions with relation to pain and blood yield.
[0102] A variety of controllable factors are known to result in
painless, efficient blood droplet yield from the skin surface.
These factors include the depth of lancet. penetration to the
vascular plexus; the manner in which the skin is stabilized prior
to lancet impact and the geometry of the lancing device. Blood
volume, success rate, pain, and wound formation may be related to
the diameter, depth and facet geometry of the lancet tip.
[0103] The preferred geometry for cutting is a three-facet design
shown and this geometry is common in the industry. Manufacture of
these types of lancets is generally by taking a rod of a given
diameter (usually 250-760 mm diameter) and grinding 8 degrees to
the plane of the primary axis to create the primary facet. The
secondary facets are then created by rotating the shaft of the
lancet 15 degrees, and then rolling over 12 degrees to the plane of
the primary facet. Other possible geometries require altering the
lancet's production parameters such as shaft diameter, angles, and
translation distance. The features of the lancet tip affect lancing
pain, cutting efficiency, wound healing and blood volume. The wound
geometry from this style of lancet is shown on page 38.
[0104] Proprietary to PTI is the relationship of the facet lengths
and angles, and the fact that there is no molded chuck on the shaft
of the lancet. These "bare" lancets are not found in the industry
today. The advantage of the PTI proprietary lancet is that wound
healing is quicker and more efficient due to the optimized
geometry. All lancets used in patient testing are quantified and
checked for precision manufacturing and the presence of burrs or
spurs, which affect performance and pain of lancing. All lancet
specifications are entered in the PTI database. For reference, A is
the primary facet length (currently not measured, but calculated in
the measurement process), B is the side facet length and C is the
bevel joint length. The angles are derived as shown in the
engineering drawing below.
[0105] Cutting efficiency is governed by the angle of the secondary
facets. The importance of the lancet tip geometry and length of C
is reflected in the complex relationship during cutting of the
stratum corneum. Measurement of a simple inflection point in power
or velocity on traversing the stratum corneum for determination of
stratum corneum thickness is not possible since the situation is
complicated by the entry of the lancet tip with respect to the
distance along the C, B and A lengths.
[0106] The facets lengths, angles and diameter of common industry
standard lancets have been measured and are shown in the Table
below. As discussed above, lancing pain and blood yield are
integrally related to these mechanical parameters. A common precept
is that the smaller the diameter of the lancet, the less lancing
pain is perceived. For a given amount of blood however, the thin
lancet must then go deeper to cut more vessels to get the same
amount of blood (this is discussed in detail in the anatomy
section). Consequently, a larger diameter lancet with a shallow
penetration will cut the desired amount of blood vessels
(capillaries) with less pain. This is confirmed in histological
cross sections of glabrous skin at the level of the papillary
dermis and deeper, by measuring the distribution of blood vessels
versus nerve branches cut for a given lancet footprint.
[0107] Pelikan Lancet
[0108] In one embodiment, decreasing shaft diameter affects
primarily the value of A, and somewhat the value of B. PTI
laboratory experiments and histological sections have confirmed
that a shallow penetration with a wide lancet (efficient cut)
translates to low pain. In one embodiment, the B manufactured
lancet of 313 mm is the lancet used in patient testing. The choice
was primarily based on the fact that the B lancet can penetrate
shallow depths (.about.600 to 800 mm) to get 1 microL of blood,
whereas the Hart and BD II were unable to perform at shallower
depths (0.5-1.0 mm) due to poor cutting efficiency. Shallow depth
settings resulted in these lancets bouncing out of the skin,
presumably due to the angle of the secondary facets and the long
bevel joint length.
[0109] The recently released BD UF III is a 200 mm diameter lancet
of different angle and facet length geometry than the BD UF II.
This is due to the fact that the grinding process described above
results in modified angle relationships due to the reduced diameter
of the shaft. To illustrate this a theoretical experiment would be
to keep the B angle ratios constant and grind these on 200 mm bar
stock to form the B III. There is a large effect on the facet
lengths if the cutting angles are kept constant. The expectation is
a quite different performance than the BD UF III, presumably again
outperforming the BD UF III on small penetration depths. Similarly,
the same thought experiment can be carried out if 200 mm bar stock
is ground keeping the ABC lengths the same as the BD UF III, using
the B grind protocol, the resulting angles are significantly
different from the BD UF III. For comparison, the B II small
diameter lancet has completely different angle and length
perspective than other B produced lancets or industry standard
offerings. Knowledge of tip geometry and facet lengths has a direct
implication on the cutting efficiency and therefore performance of
the lancet. It may very well be that there is an optimal lancet
diameter and geometry for a given penetration depth an/or skin
type.
[0110] FIG. 24 shows an embodiment with 11/2 bar. A three-facet
penetrating member design ground from half-round bar stock. The
primary angle is represented in pink, the secondary angles in blue
and as indicated by the arrows. The volume is reduced by virtue of
the fact that the bar stock is not fully round.
[0111] FIG. 25 shows a three-facet penetrating member design ground
from oval bar stock. The primary angle is represented in pink, the
secondary angles in blue. Volume reduced by using oval stock rather
than round.
[0112] FIG. 26 shows a sewing needle--volume reduced by removing
material behind the primary facet to beyond the maximum point of
penetration.
[0113] FIG. 27 shows a three spoon--volume reduction by shaving
beyond the facets.
[0114] FIG. 28 shows a C shape or half hypodermic patent needle.
Volume reduction is achieved by removing all material except that
needed for cutting and stability.
[0115] FIG. 29 shows a `smashed end` embodiment, easy to
manufacture, reduced volume.
[0116] FIG. 30 shows a table of some different dimensions,
including those of various embodiments of the present
invention.
[0117] It should be understood that any of the above penetrating
members may be adapted for use with a penetrating member driver as
described in Attorney Docket No. 38187-2551 and Attorney Docket No.
38187-2606. It should also be understood that these devices may
also be used as bare penetrating member without an additional
molded part coupled to the penetrating member. Other embodiments
may, however, be designed for use with a molded or other attachment
coupled to the penetrating member to facilitate I, handling.
[0118] While the invention has been described and illustrated with
reference to certain particular embodiments thereof, those skilled
in the art will appreciate that various adaptations, changes,
modifications, substitutions, deletions, or additions of procedures
and protocols may be made without departing from the spirit and
scope of the invention. For example, with any of the above
embodiments, the location of the penetrating member drive device
may be varied, relative to the penetrating members or the
cartridge. With any of the above embodiments, the penetrating
member tips may be uncovered during actuation (i.e. penetrating
members do not pierce the penetrating member enclosure or
protective foil during launch). With any of the above embodiments,
the penetrating members may be a bare penetrating member during
launch. With any of the above embodiments, the penetrating members
may be bare penetrating members prior to launch as this may allow
for significantly tighter densities of penetrating members. In some
embodiments, the penetrating members may be bent, curved, textured,
shaped, or otherwise treated at a proximal end or area to
facilitate handling by an actuator. The penetrating member may be
configured to have a notch or groove to facilitate coupling to a
gripper. The notch or groove may be formed along an elongate
portion of the penetrating member. With any of the above
embodiments, the cavity may be on the bottom or the top of the
cartridge, with the gripper on the other side. In some embodiments,
analyte detecting members may be printed on the top, bottom, or
side of the cavities. The front end of the cartridge maybe in
contact with a user during lancing. The same driver may be used for
advancing and retraction of the penetrating member. The penetrating
member may have a diameters and length suitable for obtaining the
blood volumes described herein. The penetrating member driver may
also be in substantially the same plane as the cartridge. The
driver may use a through hole or other opening to engage a proximal
end of a penetrating member to actuate the penetrating member along
a path into and out of the tissue.
[0119] The present invention may be used with a variety of
different penetrating member drivers. It is contemplated that these
penetrating member drivers may be spring based, solenoid based,
magnetic driver based, nanomuscle based, or based on any other
mechanism useful in moving a penetrating member along a path into
tissue. It should be noted that the present invention is not
limited by the type of driver used with the penetrating member feed
mechanism. One suitable penetrating member driver for use with the
present invention is shown in FIG. 1. This is an embodiment of a
solenoid type electromagnetic driver that is capable of driving an
iron core or slug mounted to the penetrating member assembly using
a direct current (DC) power supply. The electromagnetic driver
includes a driver coil pack that is divided into three separate
coils along the path of the penetrating member, two end coils and a
middle coil. Direct current is alternated to the coils to advance
and retract the penetrating member. Although the driver coil pack
is shown with three coils, any suitable number of coils may be
used, for example, 4, 5, 6, 7 or more coils may be used.
[0120] Referring to the embodiment of FIG. 31, the stationary iron
housing 10 may contain the driver coil pack with a first coil 12
flanked by iron spacers 14 which concentrate the magnetic flux at
the inner diameter creating magnetic poles. The inner insulating
housing 16 isolates the penetrating member 18 and iron core 20 from
the coils and provides a smooth, low friction guide surface. The
penetrating member guide 22 further centers the penetrating member
18 and iron core 20. The penetrating member 18 is protracted and
retracted by alternating the current between the first coil 12, the
middle coil, and the third coil to attract the iron core 20.
Reversing the coil sequence and attracting the core and penetrating
member back into the housing retracts the penetrating member. The
penetrating member guide 22 also serves as a stop for the iron core
20 mounted to the penetrating member 18.
[0121] As discussed above, tissue penetration devices which employ
spring or cam driving methods have a symmetrical or nearly
symmetrical actuation displacement and velocity profiles on the
advancement and retraction of the penetrating member as shown in
FIGS. 2 and 3. In most of the available lancet devices, once the
launch is initiated, the stored energy determines the velocity
profile until the energy is dissipated. Controlling impact,
retraction velocity, and dwell time of the penetrating member
within the tissue can be useful in order to achieve a high success
rate while accommodating variations in skin properties and minimize
pain. Advantages can be achieved by taking into account of the fact
that tissue dwell time is related to the amount of skin deformation
as the penetrating member tries to puncture the, surface of the
skin and variance in skin deformation from patient to patient based
on skin hydration.
[0122] In this embodiment, the ability to control velocity and,
depth of penetration may be achieved by use of a controllable force
driver where feedback is an integral part of driver control. Such
drivers can control either metal or polymeric penetrating members
or any other type of tissue penetration element. The dynamic
control of such a driver is illustrated in FIG. 2C which
illustrates an embodiment of a controlled displacement profile and
FIG. 32D which illustrates an embodiment of a the controlled
velocity profile. These are compared to FIGS. 32A and 32B, which
illustrate embodiments of displacement and velocity profiles,
respectively, of a harmonic spring/mass powered driver. Reduced
pain can be achieved by using impact velocities of greater than
about 2 m/s entry of a tissue penetrating element, such as a
lancet, into tissue. Other suitable embodiments of the penetrating
member driver are described in commonly assigned, copending U.S.
patent application Ser. No. 10/127,395, (Attorney Docket No.
38187-2551) filed Apr. 19, 2002 and previously incorporated
herein.
[0123] FIG. 33 illustrates the operation of a feedback loop using a
processor 60. The processor 60 stores profiles 62 in non-volatile
memory. A user inputs information 64 about the desired
circumstances or parameters for a lancing event. The processor 60
selects a driver profile 62 from a set of alternative driver
profiles that have been preprogrammed in the processor 60 based on
typical or desired tissue penetration device performance determined
through testing at the factory or as programmed in by the operator.
The processor 60 may customize by either scaling or modifying the
profile based on additional user input information 64. Once the
processor has chosen and customized the profile, the processor 60
is ready to modulate the power from the power supply 66 to the
penetrating member driver 68 through an amplifier 70. The processor
60 may measure the location of the penetrating member 72 using a
position sensing mechanism 74 through an analog to digital
converter 76 linear encoder or other such transducer. Examples of
position sensing mechanisms have been described in the embodiments
above and may be found in the specification for commonly assigned,
copending U.S. patent application Ser. No. 10/127,395, (Attorney
Docket No. 38187-2551) filed Apr. 19, 2002 and previously
incorporated herein. The processor 60 calculates the movement of
the penetrating member by comparing the actual profile of the
penetrating member to the predetermined profile. The processor 60
modulates the power to the penetrating member driver 68 through a
signal generator 78, which may control the amplifier 70 so that the
actual velocity profile of the penetrating member does not exceed
the predetermined profile by more than a preset error limit. The
error limit is the accuracy in the control of the penetrating
member.
[0124] After the lancing event, the processor 60 can allow the user
to rank the results of the lancing event. The processor 60 stores
these results and constructs a database 80 for the individual user.
Using the database 79, the processor 60 calculates the profile
traits such as degree of painlessness, success rate, and blood
volume for various profiles 62 depending on user input information
64 to optimize the profile to the individual user for subsequent
lancing cycles. These profile traits depend on the characteristic
phases of penetrating member advancement and retraction. The
processor 60 uses these calculations to optimize profiles 62 for
each user. In addition to user input information 64, an internal
clock allows storage in the database 79 of information such as the
time of day to generate a time stamp for the lancing event and the
time between lancing events to anticipate the user's diurnal needs.
The database stores information and statistics for each user and
each profile that particular user uses.
[0125] In addition to varying the profiles, the processor 60 can be
used to calculate the appropriate penetrating member diameter and
geometry suitable to realize the blood volume required by the user.
For example, if the user requires about 1-5 microliter volume of
blood, the processor 60 may select a 200 micron diameter
penetrating member to achieve these results. For each class of
lancet, both diameter and lancet tip geometry, is stored in the
processor 60 to correspond with upper and lower limits of
attainable blood volume based on the predetermined displacement and
velocity profiles.
[0126] The lancing device is capable of prompting the user for
information at the beginning and the end of the lancing event to
more adequately suit the user. The goal is to either change to a
different profile or modify an existing profile. Once the profile
is set, the force driving the penetrating member is varied during
advancement and retraction to follow the profile. The method of
lancing using the lancing device comprises selecting a profile,
lancing according to the selected profile, determining lancing
profile traits for each characteristic phase of the lancing cycle,
and optimizing profile traits for subsequent lancing events.
[0127] FIG. 34 illustrates an embodiment of a tissue penetration
device, more specifically, a lancing device 80 that includes a
controllable driver 179 coupled to a tissue penetration element.
The lancing device 80 has a proximal end 81 and a distal end 82. At
the distal end 82 is the tissue penetration element in the form of
a penetrating member 83, which is coupled to an elongate coupler
shaft 84 by a drive coupler 85. The elongate coupler shaft 84 has a
proximal end 86 and a distal end 87. A driver coil pack 88 is
disposed about the elongate coupler shaft 84 proximal of the
penetrating member 83. A position sensor 91 is disposed about a
proximal portion 92 of the elongate coupler shaft 84 and an
electrical conductor 94 electrically couples a processor 93 to the
position sensor 91. The elongate coupler shaft 84 driven by the
driver coil pack 88 controlled by the position sensor 91 and
processor 93 form the controllable driver, specifically, a
controllable electromagnetic driver.
[0128] Referring to FIG. 35, the lancing device 80 can be seen in
more detail, in partial longitudinal section. The penetrating
member 83 has a proximal end:95 and a distal end 96 with a
sharpened point at the distal end 96 of the penetrating member 83
and a drive head 98 disposed at the proximal end 95 of the
penetrating member 83. A penetrating member shaft 201 is disposed
between the drive head 98 and the sharpened point 97. The
penetrating member shaft 201 may be comprised of stainless steel,
or any other suitable material or alloy and have a transverse
dimension of about 0.1 to about 0.4 mm. The penetrating member
shaft may have a length of about 3 mm to about 50 mm, specifically,
about 15 mm to about 20 mm. The drive head 98 of the penetrating
member 83 is an enlarged portion having a transverse dimension
greater than a transverse dimension of the penetrating member shaft
201 distal of the drive head. 98. This configuration allows the
drive head 98 to be mechanically captured by the drive coupler 85.
The drive head 98 may have a transverse dimension of about 0.5 to
about 2 mm.
[0129] A magnetic member 102 is secured to the elongate coupler
shaft 84 proximal of the drive coupler 85 on a distal portion 203
of the elongate coupler shaft 84. The magnetic member 102 is a
substantially cylindrical piece of magnetic material having an
axial lumen 204 extending the length of the magnetic member 102.
The magnetic member 102 has an outer transverse dimension that
allows the magnetic member 102 to slide easily within an axial
lumen 105 of a low friction, possibly lubricious, polymer guide
tube 105' disposed within the driver coil pack 88. The magnetic
member 102 may have an outer transverse dimension of about 1.0 to
about 5.0 mm, specifically, about 2.3 to about 2.5 mm. The magnetic
member 102 may have a length of about 3.0 to about 5.0 mm,
specifically, about 4.7 to about 4.9 mm. The magnetic member 102
can be made from a variety of magnetic materials including ferrous
metals such as ferrous steel, iron, ferrite, or the like. The
magnetic member 102 may be secured to the distal portion 203 of the
elongate coupler shaft 84 by a variety of methods including
adhesive or epoxy bonding, welding, crimping or any other suitable
method.
[0130] Proximal of the magnetic member 102, an optical encoder flag
206 is secured to the elongate coupler shaft 84. The optical
encoder flag 206 is configured to move within a slot 107 in the
position sensor 91. The slot 107 of the position sensor 91 is
formed between a first body portion 108 and a second body portion
109 of the position sensor 91. The slot 107 may have separation
width of about 1.5 to about 2.0 mm. The optical encoder flag 206
can have a length of about 14 to about 18 mm, a width of about 3 to
about 5 mm and a thickness of about 0.04 to about 0.06 mm.
[0131] The optical encoder flag 206 interacts with various optical
beams generated by LEDs disposed on or in the position sensor body
portions 108 and 109 in a predetermined manner. The interaction of
the optical beams generated by the LEDs of the position sensor 91
generates a signal that indicates the longitudinal position of the
optical flag 206 relative to the position sensor 91 with a
substantially high degree of resolution. The resolution of the
position sensor 91 may be about 200 to about 400 cycles per inch,
specifically, about 350 to about 370 cycles per inch. The position
sensor 91 may have a speed response time (position/time resolution)
of 0 to about 120,000 Hz, where one dark and light stripe of the
flag constitutes one Hertz, or cycle per second. The position of
the optical encoder flag 206 relative to the magnetic member 102,
driver coil pack 88 and position sensor 91 is such that the optical
encoder 91 can provide precise positional information about the
penetrating member 83 over the entire length of the penetrating
member's power stroke.
[0132] An optical encoder that is suitable for the position sensor
91 is a linear optical incremental encoder, model HEDS 9200,
manufactured by Agilent Technologies. The model HEDS 9200 may have
a length of about 20 to about 30 mm, a width of about 8 to about 12
mm, and a height of about 9 to about 11 mm. Although the position
sensor 91 illustrated is a linear optical incremental encoder,
other suitable position sensor embodiments could be used, provided
they posses the requisite positional resolution and (I time
response. The HEDS 9200 is a two channel device where the channels
are 90 degrees out of phase with each other. This results in a
resolution of four times the basic cycle of the flag. These
quadrature outputs make it possible for the processor to determine
the direction of penetrating member travel. Other suitable position
sensors include capacitive encoders, analog reflective sensors,
such as the reflective position sensor discussed above, and the
like.
[0133] A coupler shaft guide 111 is disposed towards the proximal
end 81 of the lancing device 80. The guide 111 has a guide lumen
112 disposed in the guide 111 to slidingly accept the proximal
portion 92 of the elongate coupler shaft 84. The guide 111 keeps
the elongate coupler shaft 84 centered horizontally and vertically
in the slot 102 of the optical encoder 91.
[0134] Referring now to FIGS. 36A-36G, in one embodiment, the
processor determines that the skin has been contacted when the end
tip of the penetrating member has moved a predetermined distance
with respect to its initial position. If the distance from the tip
961 of the penetrating member 183 to the target tissue 233 is known
prior to initiation of penetrating member 183 movement, the initial
position of the penetrating member 183 is fixed and known, and the
movement and position of the penetrating member 183 can be
accurately measured during a lancing cycle, then the position and
time of penetrating member contact can be determined. This method
requires an accurate measurement of the distance between the
penetrating member tip 196 and the patient's skin 233 when the
penetrating member 183 is in the zero time or initial position.
This can be accomplished in a number of ways. One way is to control
all of the mechanical parameters that influence the distance from
the penetrating member tip 196 to the patient's tissue or a surface
of the lancing device 180 that will contact the patient's skin 233.
This could include the start position of the magnetic member 202,
magnetic path tolerance, magnetic member 202 dimensions, driver
coil pack 188 location within the lancing device 180 as a whole,
length of the elongate coupling shaft 184, placement of the
magnetic member 202 on the elongate coupling shaft 184, length of
the penetrating member 183 etc. If all these parameters, as well as
others can be suitably controlled in manufacturing with a tolerance
stack-up that is acceptable, then the distance from the penetrating
member tip 196 to the target tissue 233 can be determined at the
time of manufacture of the lancing device 180. The distance could
then be programmed into the memory of the processor 193. If an
adjustable feature is added to the lancing device 180, such as an
adjustable length elongate coupling shaft 184, this can accommodate
variations in all of the parameters noted above, except length of
the penetrating member 183. An electronic alternative to this
mechanical approach would be to calibrate a stored memory contact
point into the memory of the processor 193 during manufacture based
on the mechanical parameters described above.
[0135] In another embodiment, moving the penetrating member tip 196
to the target tissue 233 very slowly and gently touching the skin
233 prior to actuation can accomplish the distance from the
penetrating member tip 196 to the tissue 233. The position sensor
can accurately measure the distance from the initialization point
to the point of contact, where the resistance to advancement of the
penetrating member 183 stops the penetrating member movement. The
penetrating member 183 is then retracted to the initialization
point having measured the distance to the target tissue 233 without
creating any discomfort to the user.
[0136] Referring now to FIG. 37, a still further embodiment of a
cartridge according to the present invention will be described.
FIG. 37 shows one embodiment of a cartridge 900 which may be
removably inserted into an apparatus for driving penetrating
members to pierce skin or tissue. The cartridge 900 has a plurality
of penetrating members 902 that may be individually or otherwise
selectively actuated so that the penetrating members 902 may extend
outward from the cartridge, as indicated by arrow 904, to penetrate
tissue. In the present embodiment, the cartridge 900 may be based
on a flat disc with a number of penetrating members such as, but in
no way limited to, (25, 50, 75, 100, . . . ) arranged radially on
the disc or cartridge 800. It should be understood that although
the cartridge 900 is shown as a disc or a disc-shaped housing,
other shapes or configurations of the cartridge may also work
without departing from the spirit of the present invention of
placing a plurality of penetrating members to be engaged, singly or
in some combination, by a penetrating member driver.
[0137] Each penetrating member 902 may be contained in a cavity 906
in the cartridge 900 with the penetrating member's sharpened end
facing radially outward and may be in the same plane as that of the
cartridge. The cavity 906 may be molded, pressed, forged, or
otherwise formed in the cartridge. Although not limited in this
manner, the ends of the cavities 906 may be divided into individual
fingers (such as one for each cavity) on the outer periphery of the
disc. The particular shape of each cavity 906 may be designed to
suit the size or shape of the penetrating member therein or the
amount of space desired for placement of the analyte detecting
members 808. For example and not limitation, the cavity 906 may
have a V-shaped cross-section, a U-shaped cross-section, C-shaped
cross-section, a multi-level cross section or the other
cross-sections. The opening 810 through which a penetrating member
902 may exit to penetrate tissue may also have a variety of shapes,
such as but not limited to, a circular opening, a square or
rectangular opening, a U-shaped opening, a narrow opening that only
allows the penetrating member to pass, an opening with more
clearance on the sides, a slit, a configuration as shown in FIG.
75, or the other shapes.
[0138] In this embodiment, after actuation, the penetrating member
902 is returned into the cartridge and may be held within the
cartridge 900 in a manner so that it is not able to be used again.
By way of example and not limitation, a used penetrating member may
be returned into the cartridge and held by the launcher in position
until the next lancing event. At the time of the next lancing, the
launcher may disengage the used penetrating member with the
cartridge 900 turned or indexed to the next clean penetrating
member such that the cavity holding the used penetrating member is
position so that it is not accessible to the user (i.e. turn away
from a penetrating member exit opening). In some embodiments, the
tip of a used penetrating member may be driven into a protective
stop that hold the penetrating member in place after use. The
cartridge 900 is replaceable with a new cartridge 900 once all the
penetrating members have been used or at such other time or
condition as deemed desirable by the user.
[0139] Referring still to the embodiment in FIG. 37, the cartridge
900 may provide sterile environments for penetrating members via
seals, foils, covers, polymeric, or similar materials used to seal
the cavities and provide enclosed areas for the penetrating members
to rest in. In the present embodiment, a foil or seal layer 926 is
applied to one surface of the cartridge 900. The seal layer 920 may
be made of a variety of materials such as a metallic foil or other
seal materials and may be of a tensile strength and other quality
that may provide a sealed, sterile environment until the seal layer
920 is penetrate by a suitable or penetrating device providing a
preselected or selected amount of force to open the sealed, sterile
environment. Each cavity 906 may be individually sealed with a
layer 920 in a manner such that the opening of one cavity does not
interfere with the sterility in an adjacent or other cavity in the
cartridge 800. As seen in the embodiment of FIG. 37, the seal layer
920 may be a planar material that is adhered to a top surface of
the cartridge 800.
[0140] Depending on the orientation of the cartridge 900 in the
penetrating member driver apparatus, the seal layer 920 may be on
the top s ace, side surface, bottom surface, or other positioned
surface. For ease of illustration and discussion of the embodiment
of FIG. 37, the layer 920 is placed on a top surface of the
cartridge 800. The cavities 906 holding the penetrating members 902
are sealed on by the foil layer 920 and thus create the sterile
environments for the penetrating members. The foil layer 920 may
seal a plurality of cavities 906 or only a select number of
cavities as desired.
[0141] In a still further feature of FIG. 37, the cartridge 900 may
optionally include a plurality of analyte detecting members 908 on
a substrate 922 which may be attached to a bottom surface of the
cartridge 900. The substrate may be made of a material such as, but
not limited to, a polymer, a foil, or other material suitable for
attaching to a cartridge and holding the analyte detecting members
908. As seen in FIG. 37, the substrate 922 may hold a plurality of
analyte detecting members, such as but not limited to, about 10-50,
50-100, or other combinations of analyte detecting members. This
facilitates the assembly and integration of analyte detecting
members 908 with cartridge 900. These analyte detecting members 908
may enable an integrated body fluid sampling system where the
penetrating members 902 create a wound tract in a target tissue,
which expresses body fluid that flows into the cartridge for
analyte detection by at least one of the analyte detecting members
908. The substrate 922 may contain any number of analyte detecting
members 908 suitable for detecting analytes in cartridge having a
plurality of cavities 906. In one embodiment, many analyte
detecting members 908 may be printed onto a single substrate 922
which is then adhered to the cartridge to facilitate manufacturing
and simplify assembly. The analyte detecting members 908 may be
electrochemical in nature. The analyte detecting members 908 may
further contain enzymes, dyes, or other detectors which react when
exposed to the desired analyte. Additionally, the analyte detecting
members 908 may comprise of clear optical windows that allow light
to pass into the body fluid for analyte analysis. The number,
location, and type of analyte detecting member 908 may be varied as
desired, based in part on the design of the cartridge, number of
analytes to be measured, the need for analyte detecting member
calibration, and the sensitivity of the analyte detecting members.
If the cartridge 900 uses an analyte detecting member arrangement
where the analyte detecting members are on a substrate attached to
the bottom of the cartridge, there may be through holes (as shown
in FIG. 76), wicking elements, capillary tube or other devices on
the cartridge 900 to allow body fluid to flow from the cartridge to
the analyte detecting members 908 for analysis. In other
configurations, the analyte detecting members 908 may be printed,
formed, or otherwise located directly in the cavities housing the
penetrating members 902 or areas on the cartridge surface that
receive blood after lancing.
[0142] The use of the seal layer 920 and substrate or analyte
detecting member layer 822 may facilitate the manufacture of these
cartridges 10. For example, a single'seal layer 920 may be adhered,
attached, or otherwise coupled to the cartridge 900 as indicated by
arrows 924 to seal many of the cavities 906 at one time. A sheet
922 of analyte detecting members may also be adhered, attached, or
otherwise coupled to the cartridge 900 as indicated by arrows 925
to provide many analyte detecting members on the cartridge at one
time. During manufacturing of one embodiment of the present
invention, the cartridge 900 may be loaded with penetrating members
902, sealed with layer 920 and a temporary layer (not shown) on the
bottom where substrate 922 would later go, to provide a sealed
environment for the penetrating members. This assembly with the
temporary bottom layer is then taken to be sterilized. After
sterilization, the assembly is taken to a clean room (or it may
already be in a clear room or equivalent environment) where the
temporary bottom layer is removed and the substrate 922 with
analyte detecting members is coupled to the cartridge as shown in
FIG. 37. This process allows for the sterile assembly of the
cartridge with the penetrating members 902 using processes and/or
temperatures that may degrade the accuracy or functionality of the
analyte detecting members on substrate 922. As a nonlimiting
example, the entire cartridge 900 may then be placed in a further
sealed container such as a pouch, bag, plastic molded container,
etc . . . to facilitate contact, improve ruggedness, and/or allow
for easier handling.
[0143] In some embodiments, more than one seal layer 920 may be
used to seal the cavities 906. As examples of some embodiments,
multiple layers may be placed over each cavity 906, half or some
selected portion of the cavities may be sealed with one layer with
the other half or selected portion of the cavities sealed with
another sheet or layer, different shaped cavities may use different
seal layer, or the like. The seal layer 920 may have different
physical properties, such as those covering the penetrating members
902 near the end of the cartridge may have a different color such
as red to indicate to the user (if visually inspectable) that the
user is down to say 10, 5, or other number of penetrating members
before the cartridge should be changed out.
[0144] Referring now to FIG. 38, one embodiment of an apparatus 980
using a radial cartridge 900 with a penetrating member driver 982
is shown. A contoured surface 884 is located near a penetrating
member exit port 986, allowing for a patient to place their finger
in position for lancing. Although not shown, the apparatus 980 may
include a human readable or other type of visual display to relay
status to the user. The display may also show measured analyte
levels or other measurement or feedback to the user without the
need to plug apparatus 980 or a separate test strip into a separate
analyte reader device. The apparatus 980 may include a processor or
other logic for actuating the penetrating member or for measuring
the analyte levels. The cartridge 900 may be loaded into the
apparatus 980 by opening a top housing of the apparatus which may
be hinged or removably coupled to a bottom housing. The cartridge
900 may also drawn into the apparatus 980 using a loading mechanism
similar in spirit to that found on a compact disc player or the
like. In such an embodiment, the apparatus may have a slot (similar
to a CD player in an automobile) that allows for the insertion of
the cartridge 900 into the apparatus 980 which is then
automatically loaded into position or otherwise seated in the
apparatus for operation therein. The loading mechanism may be
mechanically powered or electrically powered. In some embodiments,
the loading mechanism may use a loading tray in addition to the
slot. The slot may be placed higher on the housing so that the
cartridge 900 will have enough clearance to be loaded into the
device and then dropped down over the penetrating member driver
982. The cartridge 900 may have an indicator mark or indexing
device that allows the cartridge to be properly aligned by the
loading mechanism or an aligning mechanism once the cartridge 900
is placed into the apparatus 980. The cartridge 900 may rest on a
radial platform that rotates about the penetrating member driver
982, thus providing a method for advancing the cartridge to bring
unused penetrating members to engagement with the penetrating
member driver. The cartridge 800 on its underside or other surface,
may shaped or contoured such as with-notches, grooves, tractor
holes, optical markers, or the like to facilitate handling and/or
indexing of the cartridge. These shapes or surfaces may also be
varied so, as to indicate that the cartridge is almost out of
unused penetrating members, that there are only five penetrating
members left, or some other cartridge status indicator as
desired.
[0145] A suitable method and apparatus for loading penetrating
members has been described previously in commonly assigned,
copending U.S. patent applications Attorney Docket 38187-2589 and
38187-2590, and are included here by reference for all purposes.
Suitable devices for engaging the penetrating members and for
removing protective materials associated with the penetrating
member cavity are described in commonly assigned, copending U.S.
patent applications Attorney Docket 38187-2601 and 38187-2602, and
are included here by reference for all purposes. For example in the
embodiment of FIG. 37, the foil or seal layer 920 may cover the
cavity by extending across the cavity along a top surface 990 and
down along the angled surface 892 to provide a sealed, sterile
environment for the penetrating member and sensors therein. A
piercing element described in U.S. patent applications Attorney
Docket 38187-2602 has a piercing element and then a shaped portion
behind the element which pushes the foil to the sides of the cavity
or other position so that the penetrating member 902 may be
actuated and body fluid may flow into the cavity.
[0146] Referring now to FIG. 39, one embodiment of a device that
may use a disc 900 is shown. This embodiment of device 1000 include
a display 1002 that shows lancing performance and setting such as
penetration depth setting the like. Various buttons 1004 may also
be placed on the housing to adjust settings and/or to activate
lancing.
[0147] It should be understood that device 1000 may include a
processor for implementing any of the control methodologies set
forth herein. The processor may control the penetrating member
driver and/or active braking device such a pads, stops, dampers,
dashpots and other mechanism to control penetrating member speed.
The characteristic phases of penetrating member advancement and
retraction can be plotted on a graph of force versus time
illustrating the force exerted by the penetrating member driver on
the penetrating member to achieve the desired displacement and
velocity profile. The characteristic phases are the penetrating
member introduction phase A-C where the penetrating member is
longitudinally advanced into the skin, the penetrating member rest
phase D where the penetrating member terminates its longitudinal
movement reaching its maximum depth and becoming relatively
stationary, and the penetrating member retraction phase E-G where
the penetrating member is longitudinally retracted out of the skin.
The duration of the penetrating member retraction phase E-G is
longer than the duration of the penetrating member introduction
phase A-C, which in turn is longer than the duration of the
penetrating member rest phase D.
[0148] The introduction phase further comprises a penetrating
member launch phase prior to A when the penetrating member is
longitudinally moving through air toward the skin, a tissue contact
phase at the beginning of A when the distal end of the penetrating
member makes initial contact with the skin, a tissue deformation
phase A when the skin bends depending on its elastic properties
which are related to hydration and thickness, a tissue lancing
phase which comprises when the penetrating member hits the
inflection point on the skin and begins to cut the'skin B and the
penetrating member continues cutting the skin C. The penetrating
member rest phase D is the limit of the penetration of the
penetrating member into the skin. Pain is reduced by minimizing the
duration of the penetrating member introduction phase A-C so that
there is a fast incision to a certain penetration depth regardless
of the duration of the deformation phase A and inflection point
cutting B which will vary from user to user. Success rate is
increased by measuring the exact depth of penetration from
inflection point B to the limit of penetration in the penetrating
member rest phase D. This measurement allows the penetrating member
to always, or at least reliably, hit the capillary beds which are a
known distance underneath the surface of the skin.
[0149] The penetrating member retraction phase further comprises a
primary retraction phase E when the skin pushes the penetrating
member out of the wound tract, a secondary retraction phase F when
the penetrating member starts to become dislodged and pulls in the
opposite direction of the skin, and penetrating member exit phase G
when the penetrating member becomes free of the skin. Primary
retraction is the result of exerting a decreasing force to pull the
penetrating member out of the skin as the penetrating member pulls
away from the finger. Secondary retraction is the result of
exerting a force in the opposite direction to dislodge the
penetrating member. Control is necessary to keep the wound tract
open as blood flows up the wound tract. Blood volume is increased
by using a uniform velocity to retract the penetrating member
during the penetrating member retraction phase E-G regardless of
the force required for the primary retraction phase E or secondary
retraction phase F, either of which may vary from user to user
depending on the properties of the user's skin.
[0150] Displacement versus time profile of a penetrating member for
a controlled penetrating member retraction can be plotted. Velocity
vs. time profile of the penetrating member for the controlled
retraction can also be plotted. The penetrating member driver
controls penetrating member displacement and velocity at several
steps in the lancing cycle, including when the penetrating member
cuts the blood vessels to allow blood to pool 2130, and as the
penetrating member retracts, regulating the retraction rate to
allow the blood to flood the wound tract while keeping the wound
flap from sealing the channel 2132 to permit blood to exit the
wound.
[0151] The tenting process and retrograde motion of the penetrating
member during the lancing cycle can be illustrated graphically
which shows both a velocity versus time graph-and a position versus
time graph of a penetrating member tip during a lancing cycle that
includes elastic and inelastic tenting. From point 0 to point A,
the penetrating member is being accelerated from the initialization
position or zero position. From point A to point B, the penetrating
member is in ballistic or coasting mode, with no additional power
being delivered. At point B, the penetrating member tip contacts
the tissue and begins to tent the skin until it reaches a
displacement C. As the penetrating member tip approaches maximum
displacement, braking force is applied to the penetrating member
until the penetrating member comes to a stop at point D. The
penetrating member then recoils in a retrograde direction during
the settling phase of the lancing cycle indicated between D and E.
Note that the magnitude of inelastic tenting indicated in FIG. 148
is exaggerated for purposes of illustration.
[0152] The amount of inelastic tenting indicated by Z tends to be
fairly consistent and small compared to the magnitude of the
elastic tenting. Generally, the amount of inelastic tenting Z can
be about 120 to about 140 microns. As the magnitude of the
inelastic tenting has a fairly constant value and is small compared
to the magnitude of the elastic tenting for most patients and skin
types, the value for the total amount of tenting for the
penetration stroke of the penetrating member is effectively equal
to the rearward displacement of the penetrating member during the
settling phase as measured by the processor 193 plus a
predetermined value for the inelastic recoil, such as 130 microns.
Inelastic recoil for some embodiments can be about 100 to about 200
microns. The ability to measure the magnitude of skin tenting for a
patient is important to controlling the depth of penetration of the
penetrating member tip as the skin is generally known to vary in
elasticity and other parameters due to age, time of day, level of
hydration, gender and pathological state.
[0153] This value for total tenting for the lancing cycle can then
be used to determine the various characteristics of the patient's
skin. Once a body of tenting data is obtained for a given patient,
this data can be analyzed in order to predict the total penetrating
member displacement, from the point of skin contact, necessary for
a successful lancing procedure. This enables the tissue penetration
device to achieve a high success rate and minimize pain for the
user. A rolling average table can be used to collect and store the
tenting data for a patient with a pointer to the last entry in the
table. When a new entry is input, it can replace the entry at the
pointer and the pointer advances to the next value. When an average
is desired, all the values are added and the sum divided by the
total number of entries by the processor 193. Similar techniques
involving exponential decay (multiply by 0.95, add 0.05 times
current value, etc.) are also possible.
[0154] With regard to tenting of skin generally, some typical
values relating to penetration depth are now discussed. A cross
sectional view of-the layers of the skin can be shown. In order to
reliably obtain a useable sample of blood from the skin, it is
desirable to have the penetrating member tip reach the venuolar
plexus of the skin. The stratum corneum is typically about 0.1 to
about 0.6 mm thick and the distance from the top of the dermis to
the venuole plexus can be from about 0.3 to about 1.4 mm. Elastic
tenting can have a magnitude of up to about 2 mm or so,
specifially, about 0.2 to about 2.0 mm, with an average magnitude
of about 1 mm. This means that the amount of penetrating member
displacement necessary to overcome the tenting can have a magnitude
greater than the thickness of skin necessary to penetrate in order
to reach the venuolar plexus. The total penetrating member
displacement from point of initial skin contact may have an average
value of about 1.7 to about 2.1 mm. In some embodiments,
penetration depth and maximum penetration depth may be about 0.5 mm
to about 5 mm, specifically, about 1 mm to about 3 mm. In some
embodiments, a maximum penetration depth of about 0.5 to about 3 mm
is useful.
[0155] In some embodiments, the penetrating member is withdrawn
with less force and a lower speed than the force and speed during
the penetration portion of the operation cycle. Withdrawal speed of
the penetrating member in some embodiments can be about 0.004 to
about 0.5 m/s, specifically, about 0.006 to about 0.01 m/s. In
other embodiments, useful withdrawal velocities can be about 0.001
to about 0.02 meters per second, specifically, about 0.001 to about
0.01 meters per second. For embodiments that use a relatively slow
withdrawal velocity compared to the penetration velocity, the
withdrawal velocity may up to about 0.02 meters per second. For
such embodiments, a ratio of the average penetration velocity
relative to the average withdrawal velocity can be about 100 to
about 1000. In embodiments where a relatively slow withdrawal
velocity is not important, a withdrawal velocity of about 2 to
about 10 meters per second may be used.
[0156] Another example of an embodiment of a velocity profile for a
penetrating member can be seen shown, which illustrates a
penetrating member profile with a fast entry velocity and a slow
withdrawal velocity. A lancing profile showing velocity of the
penetrating member versus position. The lancing profile starts at
zero time and position and shows acceleration of the penetrating
member towards the tissue from the electromagnetic force generated
from the electromagnetic driver. At point A, the power is shut off
and the penetrating member begins to coast until it reaches the
skin indicated by B at which point, the velocity begins to
decrease. At point C, the penetrating member has reached maximum
displacement and settles momentarily, typically for a time of about
8 milliseconds.
[0157] A retrograde withdrawal force is then imposed on the
penetrating member by the controllable driver, which is controlled
by the processor to maintain a withdrawal velocity of no more than
about 0.006 to about 0.01 meters/second. The same cycle is
illustrated in the velocity versus time plotwhere the penetrating
member is accelerated from the start point to point A. The
penetrating member coasts from A to B where the penetrating member
tip contacts tissue 233. The penetrating member tip then penetrates
the tissue and slows with braking force eventually applied as the
maximum penetration depth is approached. The penetrating member is
stopped and settling between C and D. At D, the withdrawal phase
begins and the penetrating member is slowly withdrawn until it
returns to the initialization point shown by E. Note that
retrograde recoil from elastic and inelastic tenting was not shown
in the lancing profiles for purpose of illustration and
clarity.
[0158] In another embodiment, the withdrawal phase may use a dual
speed profile, with the slow 0.006 to 0.01 meter per second speed
used until the penetrating member is withdrawn past the contact
point with the tissue, then a faster speed of 0.01 to 1 meters per
second may be used to shorten the complete cycle.
[0159] While the invention has been described and illustrated with
reference to certain particular embodiments thereof, those skilled
in the art will appreciate that various adaptations, changes,
modifications, substitutions, deletions, or additions of procedures
and protocols may be made without departing from the spirit and
scope of the invention.
[0160] For example, with any of the above embodiments, the location
of the penetrating member drive device may be varied, relative to
the penetrating members or the cartridge. With any of the above
embodiments, the penetrating member tips may be uncovered during
actuation (i.e. penetrating members do not pierce the penetrating
member enclosure or protective foil during launch). With any of the
above embodiments, the penetrating members may be a bare
penetrating member during launch. With any of the above
embodiments, the penetrating members may be bare penetrating
members prior to launch as this may allow for significantly tighter
densities of penetrating members. In some embodiments, the
penetrating members may be bent, curved, textured, shaped, or
otherwise treated at a proximal end or area to facilitate handling
by an actuator. The penetrating member may be configured to have a
notch or groove to facilitate coupling to a gripper. The notch or
groove may be formed along an elongate portion of the penetrating
member. With any of the above embodiments, the cavity may be on the
bottom or the top of the cartridge, with the gripper on the other
side. In some embodiments, analyte detecting members may be printed
on the top, bottom, or side of the cavities. The front end of the
cartridge maybe in contact with a user during lancing. The same
driver may be used for advancing and retraction of the penetrating
member. The penetrating member may have a diameters and length
suitable for obtaining the blood volumes described herein. The
penetrating member driver may also be in substantially the same
plane as the cartridge. The driver may use a through hole or other
opening to engage a proximal end of a penetrating member to actuate
the penetrating member along a path into and out of the tissue. The
present penetrating member may be used with multiple penetrating
member cartridges or single penetrating member cartridges. They may
be used with penetrating member cartridges which are oval, square,
rectangular, triangular, hexagonal, polygonal, or other shaped or
combinations of shapes. The penetrating members may be used in a
bandolier configuration or held in a tape containing a plurality of
penetrating members between two tapes. The penetrating members may
be used electric drive devices or conventional spring-based
launchers.
[0161] While the invention has been described and illustrated with
reference to certain particular embodiments thereof, those skilled
in the art will appreciate that various adaptations, changes,
modifications, substitutions, deletions, or additions of procedures
and protocols may be made without departing from the spirit and
scope of the invention. For example, with any of the above
embodiments, the location of the penetrating member drive device
may be varied, relative to the penetrating members or the
cartridge. With any of the above embodiments, the penetrating
member tips may be uncovered during actuation (i.e. penetrating
members do not pierce the penetrating member enclosure or
protective foil during launch). With any of the above embodiments,
the penetrating members may be a bare penetrating member during
launch. With any of the above embodiments, the penetrating members
may be bare penetrating members prior to launch as this may allow
for significantly tighter densities of penetrating members. In some
embodiments, the penetrating members may be bent, curved, textured,
shaped, or otherwise treated at a proximal end or area to
facilitate handling by an actuator. The penetrating member may be
configured to have a notch or groove to facilitate coupling to a
gripper. The notch or groove may be formed along an elongate
portion of the penetrating member. With any of the above
embodiments, the cavity may be on the bottom or the top of the
cartridge, with the gripper on the other side. In some embodiments,
analyte detecting members may be printed on the top, bottom, or
side of the cavities. The front end of the cartridge maybe in
contact with a user during lancing. The same driver may be used for
advancing and retraction of the penetrating member. The penetrating
member may have a diameters and length suitable for obtaining the
blood volumes described herein. The penetrating member driver may
also be in substantially the same plane as the cartridge. The
driver may use a through hole or other opening to engage a proximal
end of a penetrating member to actuate the penetrating member along
a path into and out of the tissue.
[0162] Any of the features described in this application or any
reference disclosed herein may be adapted for use with any
embodiment of the present invention. For example, the devices of
the present invention may also be combined for use with injection
penetrating members or needles as described in commonly assigned,
copending U.S. patent application Ser. No. 10/127,395 (Attorney
Docket No. 38187-2551) filed Apr. 19, 2002. An analyte detecting
member to detect the presence of foil may also be included in the
lancing apparatus. For example, if a cavity has been used before,
the foil or sterility barrier will be punched. The analyte
detecting member can detect if the cavity is fresh or not based on
the status of the barrier. It should be understood that in optional
embodiments, the sterility barrier may be designed to pierce a
sterility barrier of thickness that does not dull a tip of the
penetrating member. The lancing apparatus may also use improved
drive mechanisms. For example, a solenoid force generator may be
improved to try to increase the amount of force the solenoid can
generate for a given current. A solenoid for use with the present
invention may have five coils and in the present embodiment the
slug is roughly the size of two coils. One change is to increase
the thickness of the outer metal shell or windings surround the
coils. By increasing the thickness, the flux will also be
increased. The slug may be split; two smaller slugs may also be
used and offset by 1/2 of a coil pitch. This allows more slugs to
be approaching a coil where it could' be accelerated. This creates
more events where a slug is approaching a coil, creating a more
efficient system.
[0163] In another optional alternative embodiment, a gripper in the
inner end of the 25 protective cavity may hold the penetrating
member during shipment and after use, eliminating the feature of
using the foil, protective end, or other part to retain the used
penetrating member. Some other advantages of the disclosed
embodiments and features of additional embodiments include: same
mechanism for transferring the used penetrating members to a
storage area; a high number of penetrating members such as 25, 50,
75, 100, 500, or more penetrating members may be put on a disk or
cartridge; molded body about a lancet becomes unnecessary;
manufacturing of multiple penetrating member devices is simplified
through the use of cartridges; handling is possible of bare rods
metal wires, without any additional structural features, to actuate
them into tissue; maintaining extreme (better than 50
micron-lateral and better than 20 micron vertical) precision in
guiding; and storage system for new and used penetrating members,
with individual cavities/slots is provided. The housing of the
lancing device may also be sized to be ergonomically pleasing. In
one embodiment, the device has a width of about 56 mm, a length of
about 105 mm and a thickness of about 15 mm. Additionally, some
embodiments of the present invention may be used with
non-electrical force generators or drive mechanism. For example,
the punch device and methods for releasing the penetrating members
from sterile enclosures could be adapted for use with spring based
launchers. The gripper using a frictional coupling may also be
adapted for use with other drive technologies.
[0164] Still further optional features may be included pith the
present invention. For example, with any of the above embodiments,
the location of the penetrating member drive device may be varied,
relative to the penetrating members or the cartridge. With any of
the above embodiments, the penetrating member tips may be uncovered
during actuation (i.e. penetrating members do not pierce the
penetrating member enclosure or protective foil during launch). The
penetrating members may be a bare penetrating member during launch.
In some embodiments, the penetrating member may be a patent needle.
The same driver may be used for advancing and retraction of the
penetrating member. Different analyte detecting members detecting
different ranges of glucose concentration, different analytes, or
the like may be combined for use with each penetrating member.
Non-potentiometric measurement techniques may also be used for
analyte detection. For example, direct electron transfer of glucose
oxidase molecules adsorbed onto carbon nanotube powder
microelectrode may be used to measure glucose levels. In some
embodiments, the analyte detecting members may formed to flush with
the cartridge so that a "well" is not formed. In some other
embodiments, the analyte detecting members may formed to be
substantially flush (within 200 microns or 100 microns) with the
cartridge surfaces. In all methods, nanoscopic wire growth can be
carried out via chemical vapor deposition (CVD). In all of the
embodiments of the invention, preferred nanoscopic wires may be
nanotubes. Any method useful for depositing a glucose oxidase or
other analyte detection material on a nanowire or nanotube may be
used with the present invention. Additionally, for some
embodiments, any of the cartridge shown above may be configured
without any of the penetrating members, so that the cartridge is
simply an analyte detecting device. Still further, the indexing of
the cartridge may be such that adjacent cavities may not
necessarily be used serially or sequentially. As a nonlimiting
example, every second cavity may be used sequentially, which means
that the cartridge will go through two rotations before every or
substantially all of the cavities are used. As another nonlimiting
example, a cavity that is 3 cavities away, 4 cavities away, or N
cavities away may be the next one used. This may allow for greater
separation between cavities containing penetrating members that
were just used and a fresh penetrating member to be used next. For
any of the embodiments herein, they may be configured to provide
the various velocity profiles described.
[0165] This application cross-references commonly assigned
copending U.S. patent applications Ser. No. 10/323,622 (Attorney
Docket No. 38187-2606) filed Dec. 18, 2002. This application is
also related to commonly assigned copending U.S. patent
applications Ser. No. 10/335,142 filed Dec. 31, 2002. This
application is also a continuation-in-part of commonly assigned,
copending U.S. patent application Ser. No. 10/425,815 (Attorney
Docket No. 38187-2663) filed May 30, 2003. This application is
related to copending U.S. patent application Ser. No. 10/127,395
(Attorney Docket No. 38187-2551) filed Apr. 19, 2002. This
application is also a continuation-in-part of commonly assigned,
copending U.S. patent application Ser. No. 10/237,261 (Attorney
Docket No. 38187-2595) filed Sep. 5, 2002. This application is
further a continuation-in-part of commonly assigned, copending U.S.
patent application Ser. No. 10/420,535 (Attorney Docket No.
38187-2664) filed Apr. 21, 2003. This application is further a
continuation-in-part of commonly assigned, copending U.S. patent
application Ser. No. 10/335,142 (Attorney Docket No. 38187-2633)
filed Dec. 31, 2002. This application is further a
continuation-in-part of commonly assigned, copending U.S. patent
application Ser. No. 10/423,851 (Attorney Docket No. 38187-2657)
filed Apr. 24, 2003. All applications listed above are incorporated
herein by reference for all purposes.
[0166] The publications discussed or cited herein are provided
solely for their disclosure prior to the filing date of the present
application. Nothing herein is to be construed as an admission that
the present invention is not entitled to antedate such publication
by virtue of prior invention. Further, the dates of publication
provided may be different from the actual publication dates which
may need to be independently confirmed. All publications mentioned
herein are incorporated herein by reference to disclose and
describe the structures and/or methods in connection with which the
publications are cited.
[0167] Expected variations or differences in the results are
contemplated in accordance with the objects and practices of the
present invention. It is intended, therefore,.that the invention be
defined by the scope of the claims which follow and that such
claims be interpreted as broadly as is reasonable.
* * * * *